Improvement in underground-telegraph lines



PatentedJu|y15,1879.

UNITED STATES PATENT OEEIoE.

JAMES S. PIERSON, OF BROOKLYN, NEET YORK.

lMPROVEMENT IN UNDERGROUND-TELEGRAPH LINES.

Specification forming part ot' Letters Patent No. 217,479, dated July15, 1879; application lilcd November 22, 1878.

To all whom it may concern:

Be it known that l, JAMES S. PIERSON, ot' Brooklyn, in the county ofKings and State of New York, have invented an Improvement inUndergrou11d-Telegraph Lilies, of which the following is aspecification.

Telegraph wires heretofore laid in the ground have been incased innon-conducting material, and then introduced in tubes. In some instancesthese tubes have been ot' metal and laid together in sections.

My invention relates to the means for holding the wires in position,insulating them, and rendering the entire structure water-proof.

In the drawings, Figure l is a cross-section of the lines and theinclosing-case, and Fig. 2 is a plan, partially in section, of thecaseand lines.

The telegraph wires or conductors a are of copper or other material, andthe size of the underground structure will depend upon the number et'conductors.

lhe case l) is ot' either voed, metal, or earthenivare. l prefer to makethe same of wood thoroughly coated with asphalt. The sections or lengthsot' case are united by tongues and grooves at c, and india-rubber,asphalt, or other yielding material is to be inserted to keep out water,and with metal cases this yields to expansion or contraction from heator cold. The cover/'is 'preferably secured by screws.

A layer ot' melted native asphalt or bitumen is laid in the case l), andupon this a pla-nk or board, la, having numerous grooves in its uppersurface, and into these grooves the conductors a are laid. It isgenerally best to supply 'these telegraph-wires trom reels that aredrawn along the top edge ot' the pipe or case l), and planks or boards7L are laid successively upon the bitumen, the grooves matching eachother.

Meited bitumen or asphalt is poured upon the boards l1., and insutlicient quantities to till the grooves and prevent moisture reachingeither the board or the conductors.

A second board, l, is laid upon the asphalt While hot, and pressure isapplied sut'licientto cause an intimate contact between the board andthe bitumen.

The grooved boards should be laid so that the joints ot' one layer comenear the middle ot' the boards ot' the next layer.

A secondrange ot' wires is laid in the grooves in the surfaces ot' thesecond layer oi boards, l, and the filling-in ot melted bitumen is madeuse of,as before described. ln this manner several layers are introducedin the case, and then the cover is puton and fastened down, it' desired.

The bitumen, being imlestructible, entirely Water-proof', and slightlyelastic, is excellently adapted to the insulation and protection oiunderground-telegraph lines, and the risk ot' injury is lessened inconsequence of the slight elasticity of the bitumen, because the samewill yield and not crack by the settling of the earth or the frostdisplacing the case containing the conductors.

lt is to be understood that it preferable not to employ the interior orbrittle quality of bitumen or asphalt.

Lateral branches are taken oli" in the manner represented in Fig. l, thewires being laid in transverse grooves that correspond to the grooves inthe plank that pass ott' laterally.

l claim as my invention- In combination with grooved planks or boardsand the conductors in such grooves, a filling ot' asphalt introducedinto such grooves and around the boards, substantially as set forth.

Signed by me 'this 19th day of November, A. D. 1878.

JAMES S. PERSOJ.

Vifitnesses c GEO. T. PrNcKNEY, 'WILLIAM G. Mo'r'r.

